The Collaborative International Dictionary of English v.0.48:

Dodgem \Dodgem\ n.
   a small low-powered electrically powered vehicle driven on a
   special platform where there are many others to be dodged.

   Syn: bumper car.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Dodgem
    n 1: a small low-powered electrically powered vehicle driven on
         a special platform where there are many others to be dodged
         [syn: bumper car, Dodgem]